diff --git a/yarn.lock b/yarn.lock
index 0005b32..8f999a4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1107,8 +1107,8 @@ clap@^1.0.9:
     chalk "^1.1.3"
 
 clean-css@4.1.x, clean-css@^4.1.3:
-  version "4.1.7"
-  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.7.tgz#b9aea4f85679889cf3eae8b40349ec4ebdfdd032"
+  version "4.1.11"
+  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.11.tgz#2ecdf145aba38f54740f26cefd0ff3e03e125d6a"
   dependencies:
     source-map "0.5.x"
 
@@ -5165,8 +5165,8 @@ source-map-url@~0.3.0:
   resolved "https://registry.yarnpkg.com/source-map-url/-/source-map-url-0.3.0.tgz#7ecaf13b57bcd09da8a40c5d269db33799d4aaf9"
 
 source-map@0.5.x, source-map@^0.5.0, source-map@^0.5.3, source-map@^0.5.6, source-map@~0.5.0, source-map@~0.5.1, source-map@~0.5.3:
-  version "0.5.6"
-  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.6.tgz#75ce38f52bf0733c5a7f0c118d81334a2bb5f412"
+  version "0.5.7"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
 
 source-map@^0.1.38:
   version "0.1.43"